Stephen d



(No Model.)

S. D. FIELD.

PRINTING TELEGRAPH AND TRANSMITTER THEREFOR. No. 287,265. Patented Oct. 23, 188? WITNESSES:

' ATTORNEY.

UNITE STATES PATENT I OFFIC STEPHEN D. FIELD, OF NEW YORK, N. Y., ASSIGNOR'TO THE COMMERCIAL TELEGRAM COMPANY, OF SAME'PLACE.

PRINTING-TELEGRAPH AND TRANSMITTER THEREFOR.

SPECIFICATION forming part Of Letters Patent NO. 287,265, dated October 23, 1883.

I Application filed April 27, 1883. (No model.)

To all whom it may concern:

Be it known that I, STEPHEN D. FIELD, of New York, in the county of New York and State of New York, have invented a new and useful Improvement in Printing-Telegraphs and Transmitter therefor; and I do hereby declare that the following is a'full and exact description of the same, reference being had to the accompanying drawings, and to the let- .for another operation, the magnets to be affected being properly adjusted for these variations. In my present invention, however, I use neither of these plans but taking as a standard a current of any given length sufficient to operate the magnet in the circuit requiring the longest current to operate another magnet solely, I divide such current into impulses any one of which is sufficient to operate the last-mentioned magnet, but not the first one.

My invention therefore relates to anovel method of affecting two operations-one by what may be termed a whole impulse, and the other by what may bev termed semi-impulses to means whereby at will either such whole impulses or semi-impulses may be transmitted over the line, and to an arrangement of magnets for utilizing such different characters of impulses over one wire.

In carrying my invention into effect I use, primarily, any well-known form of reversingkey properly connected to a battery, and also to the line, through tlie'devices hereinafter de scribed. For use with printing-telcgraphs, the type may be of the well-known reversingkey-that is, a key actuated by a motive power and escapement. Instead, however, of one pair of springs, as is usual, Iuse two. Of these, the first pair is connected one to either pole of a battery, whose center is connected to the ground, while the key itself is connected to the line, as hereinafter explained. The

second pair is arranged so that each contacts with a common anvil, forming electrical connection between them, and arranged so that one is lifted from such common anvil just after the key has made contact with one of the springs referred to, and to return to such anvil just before the key and spring break contact. The key-lever, however, is connected, primarily, to the line through one of this secondpair of springs, their common anvil, and the sec ond spring of this pair. In such construction the key, when in operation, always lifts one of the second pair of springs from the com mon anvil, breaking the electrical connection i between them just after it has formed electrical connection from the battery to line through contacting with one of the first pair of springs. The result of this is that each impulse is cut in two-that is, immediately after contact is made between the key-lever and one of the first pair of springs, the circuit isbroken at one of the second pair of springs, sending a short impulse, while, as the key returns, this break at the second pair is closed, and immediately thereafter the circuit is broken at the first pair, the currents sent being graphically represented by two dots instead of a dash. The two springs of the second pair, however, are also electrically connected by a second circuit, which is a shunt to the circuit through their common anvil, this shuntcircuit containing a key, whose lever and back stop are normally in the circuit and maintain it closed. The result of this is that so long as the key is unused a circuit direct from the re versing-key to line is maintained without re gard to the operation of the reversing-key lever upon the second pair of springs referred to, so that during such period currents of 0 maximum length of duration are sent to line.

If, however, this key be operated, this second or shunt circuit is broken, and the only path to line for each impulse is through the two" pairs of springs, whereupon each impulse is 5 broken, or, as it were, chopped in two. To utilize this principle in a receiving-instrument, I use a step-by-step printing-telegraph of one or more type-wheels, actuated by any suitable motor and controlled by an escape IOO ment and polarized magnet. In the same circuit is arranged the unison-magnet, the

ticular actions are only typical, as any other two actions may be accomplished over the same wire upon the same principle. These things are conventionally illustrated in the drawings, in which' Figure 1 shows, mainly in diagram, atransmitter and a receiver embodying my invention, while Figs.'2 and 3 are graphic representations of the whole and the semi impulses sent by the transmitter.

In Fig. 1, To" is the. transmitter. arm A is on a shaft driven by proper motive power, to which shaft is secured the escapewheel A, actuating the anchor B, pivoted at 1 used, the shunt around D is broken and semiimpulses are sent-'that is, each reversed current is in two impulses, the first of which affects It, the second simply holding R in the b, and terminating in the key-lever B,- which carries contacts z' 2', arranged to' take on the contacts 6 e of the first pair of springs, E E,

. and form therewith a reverser for the battery V, which is here shown as a divided battery, having a ground-connection, 6, from its eenter, while its 0 and Z ends are connected to E and E, respectively.

Upon the free or farther end of B are arranged, one on each side, the insulating-pieces c 0, arranged to take under the second pair of springs, O G, and lift one or the other thereof, according'to the direction of movement of B from the anvil D, common to and electrically connecting both of them.

From the lever B an electrical connection is made to one of this second pair of springsin this case O:while from it to the other spring--l1ere C"-an electrical connection is formed through a key, It, and its back stop a".

The lever B and its contacts and the springs E E G G are so adjusted that 13, immediately after contacting with E or E, shall lift the springs O or O, the one on the corresponding side from the anvil D, and thereby break the connection between themand between B and the line through the anvil D. So long, however, as the key R is in the position shown j ment of B it will be made again at D, just before being broken at c or e, and P or N of Fig. 3 will be divided into semi-impulses, as p p a n in Fig. 2.

In the receiver R is illustrated a device for making use of these two characters of current,

. net U M in the escapement-circuit 5 5.

an escapement and a unison device being chosen as types. l I? M represent the polarized magnet actuating the armature and escapement R, controlling the escape-wheel T, upon a shaft upon which a type-wheel, W, (indicated in dotted lines is mounted.

Upon the type-wheel shaft is an arm,'m, adapted to take into and catch upon a hook,

h, at the free end of an amature-lever, h, when such lever is held by the resilience of the spring S against the action of the unison mag The spring 8 and the magnetic strength of U M are so adjusted relatively to each other that it requires what has been called hereinbefore a whole impulse to charge U M suificiently to attract 71 and thereby keep the unison mechanism m h out of operation. In it the 1 The result of this is that so long as the key R at the transmitting-station is not used whole impules are I sent and U M attracts h, keeping h and m from acting upon each other. If, however, R be position given it by the first, and neither of which is suflicient to cause U M to hold h whereupon the spring 8 places h in' position to check the type-wheel train and type-wheel at the designated or unison point, from which it a is released by simply allowing R to resume its 1 normal position.

By thus changing an impulse from its total character, or a whole impulse, to aseries of semi or fractional impulses, in contradistinction to reversing a current, to

augmenting it, or to polarizing it, I am able,

;without interference with or stoppage of the transmitter, to accomplish two independent operations over one line.

Having thus described my invention, what I claim, and desire to secure by Letters Patent,

1. In a transmitter, the combination of a pair of springs connected one to each end of a battery, akey-lever, a second pair of springs, and an anvil adapted to normally connect them and a shunt-circuit to the anvil controlled by a key, substantially as set forth.

2. The combination,withacurrent-reverser,

of a second pair of springs normally electrically connected and adapted to be separated by the key-lever, and an independent electrical connection controllable at will to send two different characters of electrical impulses upon the line, substantially as set forth.

3. In a telegraph-transmitter, the combina :tion of a eurrent-reverser, a second pair of springs, one of which is connected to the keylever of the transmitter and the other to the line, a common anvil normally electrically connecting them, and an independent controllable connection between them, substantially as set forth.

4. The combination, in one circuit, of atransmitter provided with means for dividing at This specification signed and witnessed this will its normal or full pulsations, as described, 3d day of April, 1883.

and a receiver having two magnets in such circuit, one adapted to operate with either the STEPHEN D. FIELD. 5 normal or the divided pulsations, and the other Witnesses:

with normal or full pulsations only, substan- GEO. NV. CASPER,

tially as set forth. LUTHER E. SHINN, 

